Mobile content is any type of media that is viewed or used on mobile devices, such as ringtones, graphics, discount offers, games, movies, and GPS navigation. As mobile phone use has grown since the mid 1990s, the significance of the devices in everyday life has grown accordingly. Owners of mobile phones can now use their devices to make calendar appointments, send and receive text messages (SMS), listen to music, watch videos, shoot videos, redeem coupons for purchases, view office documents, get driving instructions on a map, and so forth. The use of mobile content has grown accordingly.
With the advent of faster mobile networks, having video displays on small screen devices has become more and more practical. Mobile video comes in several forms including 3GPP, MPEG-4, Real Time Streaming Protocol (RTSP) and Flash Lite. Mobile video can also be transmitted and received come in the form of streaming video programming over a mobile network. Live video can also be streamed and shared via cell phones.
Subtitles are textual versions of the dialog in films and television programs, usually displayed at the bottom of the screen. They can either be a form of written translation of a dialog in a foreign language or a written rendering of the dialog in the same language, with or without added information to help viewers who are deaf and hard-of-hearing to follow the dialog, or to assist people who cannot understand the spoken dialogue or who have accent recognition problems to understand the programming. Closed captioning is the process of displaying text on a television, video screen or other visual display to provide additional or interpretive information to individuals who wish to access it. Closed captions typically show a transcription of the audio portion of a program as it occurs (either verbatim or in edited form), sometimes including non-speech elements. Generally, subtitles are graphics that appeal in the video picture itself, while closed captioning are transmitted as data along with the video signal and are inserted in the video image by the receiving device.